Hi readers! Today we will discuss about the OEE. The Full form of OEE is Overall Equipment Effectiveness. OEE is mostly used in TPM and a key requirement of IATF 16949, a key Indicator of manufacturing performance.
What is the use of OEE?
It is a globally accepted best practice which is used to measure the percentage of planned production time that is truly productive.
“If you can’t measure it, you can’t improve it”. Machine/Equipment performance can be easily measured with the help of OEE, once a measurement is done then we will be able to tell that how much further improvement can be done.
There is a three major component of OEE, which is listed below.
- Availability (ROA)
- Performance (ROP)
- Quality (ROQ)
Formula of OEE = ROA x ROP x ROQ
Unit of measurement of OEE is percentage (%).
Let us understand with one an example. Suppose XYZ is a plastic molding company. The running time of a single shift is 8 hours or 480 Mins. Lunch & Teatime in each shift are 40 mins. Equipment failure and set up change are 30 mins and 15 mins respectively (in a shift). The cycle time of a unit is 0.75min/unit. In a single shift 500 units is being produced. 25 units/shift are rejected products. Then calculate the OEE of the machine.
Step to calculate the OEE.
Step 1 – Calculate ROA
Availability (ROA) = (Loading time – Down time)/Loading time
Loading time = 480- 40 = 440 mins
Equipment failure and set up change are = 30+15 = 45 Mins
So, Availability (ROA) = (Loading time – Down time)/Loading time
= (440 – 45)/440 = 0.90
Step – 2 Calculate ROP
Performance = (Theoretical cycle time x processed unit) /Operating time
Operating time = Loading time – down time = 440-45 = 395 mins
ROP = (.75min/unit x 500 Units)/Operating time
= 375/395 =0.95
Step – 3 Calculate ROQ
Quality = (Processed unit – rejected unit)/Processed unit
= (500-25)/500 =0.95
Step – 4 Calculate OEE
OEE = 0.90 x 0.95 x 0.95 = .81 = .81 *100 = 81%.